4.5.1 Arithmetic Expressions

• Binary operations, such as + - * / cannot mix signed and unsigned operands. That is, U*N is illegal if U is declared UNSIGNED, and N is a signed INTEGER.

  • Use the UNSIGNED intrinsic function to combine mixed operands in a binary operation, as in U*UNSIGNED(N)

  • An exception is when one operand is an unsigned integer and the other is a signed integer constant expression with positive or zero value; the result is an unsigned integer.

  • The kind of the result of such a mixed expression is the largest kind of the operands.

  Exponentiation of a signed value is signed while exponentiation of an unsigned value is unsigned.

• Unary minus of an unsigned value is unsigned.

• Unsigned operands may mix freely with real, complex operands. (Unsigned operands cannot be mixed with interval operands.)